1. Technical Field Disclosure
The present disclosure relates to a dehumidifying unit, a layered temperature control dehumidifying element, a drying device and a temperature control method thereof.
2. Description of Related Art
As industrial manufacturing processes are developed toward a trend of high automation and high precision, manufacturing spaces and devices require high-quality air to ensure a high yield. Therein, humidity of compressed air is an important factor influencing a variety of processes. Therefore, humidity control has become an important research topic.
Generally, a conventional adsorption type compressed air drying device has two adsorption towers for adsorbing moisture of compressed air. An adsorbent, such as silica gel, zeolite or activated carbon, is filled in the adsorption towers. The adsorbent is used for dehumidifying air by adsorption and capable of being regenerated by desorption. After compressed air having a high moisture content enters into one of the adsorption towers through pipelines, the moisture content is adsorbed to dehumidify the compressed air. Then, the dehumidified compressed air is directed to a reservoir for storage. Further, when the adsorption tower reaches a saturated adsorption, a heater is generally used to heat the adsorbent inside the adsorption tower to desorb moisture from the adsorbent and regenerate the adsorbent. To perform the moisture desorption and adsorbent regeneration process, air to be used for the process is first heated by radiation, convection or heat and mass transfer to a moisture desorption temperature and then introduced into the adsorption tower for moisture desorption and adsorbent regeneration. After the process, the compressed air with high temperature and high humidity is discharged out of the adsorption tower, and the adsorbent is ready for another air dehumidifying process.
However, during transmission of the hot air to be used for the moisture desorption and adsorbent regeneration process, heat and mass transfer easily occurs between the hot air and pipeline walls, thus causing an energy loss. Further, during the moisture desorption and adsorbent regeneration process, heat is transmitted to the adsorbent by hot air convection. As such, a non-uniform temperature distribution easily occurs. For example, the temperature at the hot air inlet port is highest and the temperature at the outlet port is lowest, thereby prolonging the regeneration time. Furthermore, during the heating process, lower-temperature waste air must be discharged first, thus increasing the energy consumption of the conventional adsorption type compressed air drying device.
Therefore, how to overcome the above-described drawbacks has become critical.